vec4 colorPixel = texture2D( gm_BaseTexture, v_vTexcoord );
    vec4 colorResult = colorPixel;
    vec4 colorHSV = vec4( rgb_to_hsv( colorPixel.rgb ), colorPixel.a);

    for (int i=0; i<maxcolors; i+=1)
    {
        vec4 colorInHSV = vec4( rgb_to_hsv( colorIn[i].rgb ), colorIn[i].a);
        vec4 colorDelta = colorHSV - colorInHSV;

        if (abs(colorDelta.r)>0.5) colorDelta.r -= sign(colorDelta.r);

        if ( all( lessThanEqual( abs(colorDelta), colorTolerance[i] ) ) )
        {
            vec4 colorOutHSV = vec4( rgb_to_hsv( colorOut[i].rgb ), colorOut[i].a);

            colorResult = mix( colorOut[i],
                              vec4 ( hsv_to_rgb( vec3( mod( colorOutHSV.r + colorDelta.r, 1.0 ),
                                                     clamp( colorOutHSV.g + colorDelta.g, 0.0, 1.0 ),
                                                     clamp( colorOutHSV.b + colorDelta.b, 0.0, 1.0 ) ) ),
                                     clamp( colorOut[i].a + colorDelta.a, 0.0, 1.0) ),
                              blend[i] );
        }
    }